Activists say the proposal would negatively impact Chinatown.
"Today we're seen not just the Chinese community, but the Jewish community came out to support us people, from all different ethnic groups," said Michael Zhang, an activist and Chinatown supporter.
The "No Arena In Chinatown Solidarity" group is marking December 25 as a day of action, celebrating Chinatown's history and culture. It's something activists say will disappear if an arena for the 76ers is built in Center City.
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Up close: Debate over proposed 76ers arena near Chinatown heats up
"As you can see Chinatown is history, it's community, it's our culture here, and this is our home," said Zhang.
The proposed $1.3 billion arena would sit along Market Street between 10th and 11th streets, neighboring Chinatown.
Zhang says something very similar happened in Washington, DC. After the arena was built in Chinatown in DC, it hasn't been the same, activists say.
People of the Jewish community say Sunday's event is about supporting one another regardless of your background.
"As a Jewish person I support other communities who want to have self-determination. I feel an allegiance to the people I know are here and I think Chinatown has value to the whole city," explained Sukey Blanc.
At a meeting nearly one week ago, developers spoke out about trying to be good corporate citizens, saying if they don't buy the lot of land someone else will without consulting with the community. The Sixers argue the arena will help the city.
SEE ALSO: Fiery Chinatown meeting over Sixers arena proposal
Fiery Chinatown meeting over Sixers arena proposal